This example visualizes the Iris dataset using a parallel coordinate plot, where each flower’s measurements are drawn as a colored line across four vertical axes representing sepal length, sepal width, petal length, and petal width. The lines are color-coded by species using a d3.scaleOrdinal with a custom purple-to-yellow palette. Two dropdown menus and a button let users swap the order of any two axes, rebuilding the chart via d3.line and d3.scalePoint. The visualization is rendered with SVG and uses d3.axisLeft for tick marks.